Studies have shown that if I am a doctor and a patient comes to my office, doesn't have a huge wait, I am very friendly and attentive, I smile, I ask lots of questions, I listen well, I am compassionate, confident in appearance, and enthusiastic about prescribing something,

then >70% of my patients will claim high satisfaction and relief from pain, even if the medication I give them is sugar pills.

If you want to feel better, then you think you are indeed getting better, with a little confidence.

I think that a lot of successful acupuncture care-givers have exceptional bedside manner, and thus patients swear by them.

Just my opinion, but one backed by my read of many similar studies of placebo effects in disorders prone to good outcomes in the absence of standard treatment (intermittant pain, depression, anxiety, etc.)

ot:
Accupuncture has shown some effectiveness in the treatment of animals as well as humans, showing the placebo implication to be without merit. It may not be the most effective treatment in the world but it is effective for some things.

Totally off topic and personal opinion: Alternative treatment therapies like homeopathy, acupressure/acupuncture, ayurvedic remedies are completely undermined by Big Pharma as it is in no way going to play a role in their profit margin. They have such a strangle hold on what the population can get as a part of healthcare and will do so only if it lines their pockets: For example take a look at the stevia (natural sweetener) episode.

Look at the number of drugs that are recalled every year by these big pharmas

I know a ton of people that have benefited from acupuncture for a variety of maladies. The best approach is the combination of traditional medicine and "alternative" measures. I know two acupuncturists/physicians from China and they kick azz.